D efinition — Early separation of the placental disk from the underlying maternal surface. Clinical Features Epidemiology Placental abruption is a relatively common event, with an overall incidence of 1%. Numerous predisposing factors are thought to lead to abruption but the focus recently has been on chronic inflammatory changes such as infarcts, decidual necrosis, and inflammation in the membranes and cord vessels. Bleeding early in pregnancy…

D efinition — Metabolic deficits within the fetus that lead to the accumulation of a metabolite, typically visible in the placental villi. Clinical Features Epidemiology Lysosomal storage disorders and their placental presentations are rare events. The vast majority of cases are genetic disorders that manifest in placental findings. You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership…

D efinition — Infection resulting from the spirochete Treponema pallidum . Clinical Features Epidemiology The frequency of congenital syphilis in developed countries is much lower; however, a recent rise in the incidence has been noted. It is rarely encountered in our practice. You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log…

D efinition — Infiltration of the intervillous space by a monomorphic population of histiocytes. Clinical Features Epidemiology Uncommon. Histiocytic intervillositis is associated with spontaneous abortion and recurrent pregnancy loss. Rare cases of maternal malaria or recurrent sepsis have been documented. You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

D efinition — Maternal chronic inflammatory cells within terminal villi, not attributable to any known infection. Clinical Features Epidemiology Present in 5% to 10% of examined placentas. More often seen in women with autoimmune disorders such as systemic lupus erythematosus. Thought by some to be an autoimmune phenomenon, and some authors consider it a maternal-placental graft rejection. Others suspect that chronic villitis (CV) represents a response…

PITFALL D efinition — Placental infection by the gram-positive bacteria Listeria monocytogenes . Clinical Features Epidemiology Placental infection with Listeria is an uncommon occurrence. The most common method of infection is ingestion of unpasteurized dairy products, although deli meats and unwashed vegetables have also been implicated. Listeria is thought to spread hematogenously from mother to fetus. You’re Reading a Preview Become a Clinical Tree membership for…

D efinition — Infection by any species of Candida during the gestational period. Clinical Features Epidemiology Vaginal infection by Candida is common and is thought to occur in up to 25% of all pregnancies. Ascending infection of the placenta and/or fetus is rarer and occurs in less than 1% of all candidal infections during pregnancy. Risk factors for candidal chorioamnionitis include concurrent vaginal infection, cervical cerclage,…

D efinition — Ascending infection of the amniotic fluid leading to a fetal and maternal inflammatory response. Clinical Features Epidemiology Acute chorioamnionitis (ACA) is detected in approximately 25% of preterm deliveries, and gestational age of babies born with ACA is significantly younger than those born without ACA. Chorioamnionitis is a common end outcome of several infectious agents. May occur at any stage during pregnancy. Common cause…

D efinition — Diffuse or multifocal fibrin deposition that fills and obliterates the intervillous space along a significant portion of the chorionic plate. Clinical Features Epidemiology Uncommon (less than 1% of placentas). Occasionally associated with abnormal maternal clotting (APhA, ATIII deficiency). You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in…

D efinition — Detached strips of amniotic membrane that restrict fetal growth, resulting in asymmetric anomalies that do not follow a recognized developmental pattern. Clinical Features Epidemiology One in 2,500 to 10,000 deliveries. You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

PITFALL D efinition — Thrombus formation within the umbilical cord, within its tributaries on the placental surface, or within stem villi. Clinical Features Epidemiology Common; seen in 3% to 10% of placentas. Increased incidence with maternal diabetes. You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

D efinition — Umbilical cord with two vessels; one umbilical artery and one vein. Clinical Features Epidemiology Common; noted in 1% to 3% of all gestations. More frequent in spontaneous abortions. More frequent in white women than black or Asian women. You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in…

D efinition — True knots in the umbilical cord. Clinical Features You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

D efinition — Benign expansile nodule of capillaries and stromal cells. Clinical Features Epidemiology Uncommon; this finding is seen in less than 0.5% of placentas. Associated with twin gestations and preeclampsia. You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

D efinition — A subset of extravillous trophoblastic tumor that is thought to arise from an extravillous (transitional) trophoblast that forms a transition from villous cytotrophoblast to mature extravillous trophoblast. These cells are found in the chorionic membrane, maternal surface of the placenta, and where intervillous fibrin is deposited. Clinical Features Epidemiology Rare. Occurs in reproductive-age women. Epithelioid trophoblastic tumors (ETTs) are an unusual type of…

D efinition — An abnormal early implantation site (IS) that can be identified in the setting of a molar pregnancy. Clinical Features Epidemiology Atypical molar ISs may be seen in the setting of any molar pregnancy. They are much more common in the background of a complete hydatidiform mole, seen in at least two thirds of cases versus less than 20% of partial moles. You’re Reading…

PITFALL D efinition —A malignancy that arises from the early implantation site extravillous trophoblasts. Clinical Features Epidemiology Placental site trophoblastic tumors (PSTT) are rare and were only recognized as a malignancy in 1981. PSTT are most commonly seen following a normal term delivery. Occasional cases follow spontaneous abortions, therapeutic abortions, and ectopic or molar pregnancies. Most cases are seen in reproductive-age women, although rare cases are…